Evidential Bases & e/m
(promoting evidence-based reasoning)
Dr. Frank Jenkins (retired)
Centre for Mathematics Science
and Technology Education (CMASTE)
Secondary Education, U of A
Edmonton Physics Teachers, 2011-10-12
“Evidence”: the most important word in science
Often teachers do not find time (or lack
the resources) to present evidence for
their claims to knowledge to students.
 The pedagogic purpose of this
presentation is to increase teacher
awareness, understanding and action
on a variety of ways to present evidence
in the classroom (with no excuses).

CMASTE Evidential Base Project
E.g., e/m ratio of the electron
1.
2.
3.
4.
5.
6.
thought
experiment
demonstration
wet lab (actual)
dry lab (lab
exercise)
simulation/
animation (Word)
video lab (YouTube)
photo lab
8. photo analysis
9. computer
probes/sensors
10. field trip (UofA e/m)
11. primary literature
12. remote access
7.
(computer control of remote e/m equipment)
Use this page to access e/m examples.
1. A thought experiment
 to describe and explain the experiment and even predict the
results for the experiment
 includes talk, hand-waving, equations, and diagrams
 used often in classrooms due to efficiency and low cost
I
A

BE
Figure 1: e/m tube
(applying a magnetic
field to bend an electron
beam in a circle)

BH
Figure 2: Alignment of

Helmholtz Coils
(balancing Earth and
Helmholtz magnetic fields)
1. A thought experiment
Advantages
A thought exp. may:
 save time and money
 be completely oral
 require hand waving
 require a diagram
 require equations
 may accompany a
static demonstration
 be used pre/post lab
Disadvantages
A thought exp. may not:
 suit visual learners
 suit tactile learners
 suit slower learners
 improve lab/tech skills
 improve inquiry skills
 realistically portray the
nature of science
 be used to test concepts
2. A demonstration
Advantages
A demonstration may:






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

save time
save money
Improve accuracy
improve reliability
improve attention
improve learning
be good PD for the teacher
demonstrate KSAs
allow for student
participation
Disadvantages
A demonstration may not:
(relative to a student lab)
 suit the learning style of some
learners
 allow for student participation
 allow the learning of
manipulative skills
 promote deep understanding
 promote evidence-based
reasoning
 promote scientific attitudes
3. A “wet” (student) lab
Advantages
A wet lab may:

promote scientific
attitudes
 allow for assessing
technological skills
 reinforce learning
 increase interest
 increase knowledge of
scientific inquiry
Disadvantages
A wet lab may not:
 save time
 save money
 promote order
 create a safe
environment
 suit teachers who are
without the required
laboratory KSAs
4. A “dry” lab—lab exercise
--providing parts of a lab report
Advantages
A lab exercise may:





save time & money
emphasize the need for
evidence
promote Analysis or any
other parts of a laboratory
report
be used in all assessment
tools (e.g., quizzes & tests)
improve the writing of lab
reports
Disadvantages
A dry lab may not:


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


promote technological skill
development
promote scientific attitudes
promote scientific inquiry
promote confidence in
laboratory work
reveal the interaction of
science & technology
replace laboratory work
Hints: (1) Use simulations to provide “evidence” of creating
the lab exercises. (2) No test should be without a lab exercise.
5. A simulation/animation
 computer based
Advantages
A simulation may:







save time & money
introduce or reinforce real
laboratory work—pre/post
help visual learners
help learning at a distance
be repeated as many
times as required (7/24)
be used as an assessment
tool (from the screen)
be good PD for teachers
Disadvantages
A simulation may not:






promote laboratory skill
development
promote scientific attitudes
promote scientific inquiry
promote confidence in
laboratory work
reveal the interaction of
science & technology
be accessible to some schools,
classrooms & learners
6. A video lab
 computer based or not
Advantages
A video-lab may:







save time & money
introduce or reinforce real
laboratory work—pre/post
help visual learners
help learning at a distance
be repeated as many
times as required
be created by students or
teachers with new-tech
be good PD for teachers
Disadvantages
A video-lab may not:






promote laboratory skill
development
promote scientific attitudes
promote scientific inquiry
not include a quantitative
component (just qualitative?)
promote confidence in
laboratory work
be accessible to some schools,
classrooms & learners
7. A photo lab
 computer- or paper-based
Advantages
A photo-lab may:







save time & money
introduce or reinforce real
laboratory work—pre/post
help visual learners
be repeated as many
times as required (7/24)
be used in assessments
be created by students or
teachers with new-tech
be good PD for teachers
Disadvantages
A photo-lab may not:







promote laboratory skill
development
promote scientific attitudes
promote scientific inquiry
not include a quantitative
component (just qualitative?)
imitate laboratory work
provide the required action(s)
be accessible to some schools,
classrooms & learners
8. A video- or photo-lab analysis
 computer-based analysis
Advantages
A photo analysis may:







save time & money
introduce or reinforce real
laboratory work—pre/post
help visual learners
be repeated as many times
as required (7/24)
be used in assessments
include quantitative analysis
interest those with cameras
Disadvantages
A video analysis may not:






promote laboratory skill
development
promote scientific attitudes
promote scientific inquiry
imitate laboratory work
show the full complexity of real
laboratory work
be accessible to some schools,
classrooms & learners without
the required digital technology
10. A computer probe lab
 computer-based (hand held?)
Advantages
A probe/sensor lab may:






introduce or reinforce real
laboratory work—pre/post
help tactile & visual learners
introduce higher technology
to the laboratory
promote field work (where
evidence is retrieved later)
include quantitative analysis
be good PD for teachers
Disadvantages
A probe/sensor lab may not:






save time and money
promote basic laboratory skills
be accessible without field-trip
work (e.g., to rivers & ponds)
be accessible to some schools,
classrooms & learners without
the required money/technology
be accessible to individual
students (e.g., demos only)
be robust enough for student
use
11. A primary-literature lab
 using academic research reports
Advantages
A primary-lit lab may:

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

save money (and time?)
reflect real-world science
introduce or reinforce
laboratory work—pre/post
promote science history
promote science biography
promote science language
promote scientific attitudes
include quantitative analysis
be good PD for teachers
Disadvantages
A primary-lit lab may not:






promote basic laboratory skills
promote real scientific inquiry
interest some students
be accessible to students with
low reading abilities
be accessible to students
unless the primary literature
(PL) is adapted (APL)
be accessible unless it is
classical (new reports require
licensed access to journals)
12. A remote-access (Internet) lab
 using equipment remotely (with video)
Advantages
Disadvantages
A remote-access lab may: A remote lab may not:







save money and time
introduce or reinforce
laboratory work—pre/post
access high-tech equipment
help tactile/visual learners
help learning at a distance
be repeated as many times
as required (7/24)
be good PD for teachers






promote laboratory skill
development
promote scientific attitudes
promote scientific inquiry
promote confidence in
laboratory work
be accessible to some schools,
classrooms & learners
be provided by universities that
are short of cash/technicians
Evidence-Based Reasoning
My experience is that there are many
students, teachers and in the public who
do not understand the importance of
evidence-based reasoning; e.g.,
 psychic fairs, pseudoscience, astrology
 climate-change deniers
 lack of understanding of what research
is about, even in their field of work
Evidential-Bases: Advantages







removes excuses for not including laboratory
work (& evidence) in science courses
promotes “evidence” as an important word
and concept central to science
promotes evidence-based reasoning
promotes laboratory work/inquiry
promotes scientific attitudes
promotes scientific language
promotes the nature of science
Q: Where does evidence get applied?
A: Everywhere!
In the classroom:
 curriculum
 instruction
 teacher language
 in worksheets
 lab exercises
 student language
 media samples, …
In textbooks:
 text (e.g., language)
 visuals (e.g., photos)
 laboratory work
In tests/assessments
 lab exercises
 simulations
 photos or video
Evidential Bases for CTU Cycle
Lab
Type
Linear
Angular
Light Spin
Momentum Momentum & Orbital AM
Create computer
simulation
(I)
use falsifying
evidence
use falsifying
evidence
Test
verify in the
(HI/HD)
demonstration
Use
quantitative
in computer
qualitative
analysis in lab probe analysis analysis in the
exercise (exam)
laboratory
(D)
Test
(HI/HD)
falsify in the
laboratory
verify by video verify with
or photo
evidence from
analysis
primary lit
falsify via a
thought experiment
falsify by
remote access
A lab program for a major concept
Evidential
Base
Create
(inductively)
Test (verify)

“wet” lab
“dry” lab


simulation
video lab
photo lab
video analysis
comp. probes
field trip
primary lit.
remote access
Test (falsify)

thought exp.
demonstration
Use
(deductively)


Your Turn: Present the evidence
on [any concept].
1.
2.
3.
4.
5.
thought
experiment
demonstration
dry lab (lab
exercise)
wet lab (actual)
simulation/
animation
video analysis
7. video evidence
8. photo evidence
9. computer probes
10. field trip
11. primary literature
12. remote access
6.
Evidence-based language
 to be used in the classroom and laboratory

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


“Based upon Lab 6.2, we
know that ….”
“According to the research
conducted by ….”
“Peer reviewed research in
Nature suggests that ....”
“This was only an initial
(unreplicated) study but ....”
“Our interpretation of the
evidence is that ….”
“Careful control of all known
variables suggests that ….”





“This is only a correlational
study and not a cause and
effect study so ....”
“If [procedure] and
[evidence], then [analysis].”
“Anecdotal evidence
suggests that ….”
“The certainty communicated
is three significant digits.”
“We use evidence to create
and test a concept before we
go on to use it.”
Evidence-based science education
Acknowledgements
 CMASTE
 Dr. Wytze Brouwer
 Dr. Isaac-Yakoub
Isaac
 Dr. Brian Martin and
his students at
Kings Univ. College
 Hans van Kessel
 my students
Contact me:
 Dr. Frank Jenkins

fjenkins@ualberta.net
Websites

www.CMASTE.ca (general)
– Evidential Bases (specific)


www.KCVS.ca (see e/m)
www.CRYSTALAlberta.ca